PCI: tegra194: Increase LTSSM poll time on surprise link down

PCI: tegra194: Increase LTSSM poll time on surprise link down

On surprise link down, LTSSM state transits from L0 -> Recovery.RcvrLock ->
Recovery.RcvrSpeed -> Gen1 Recovery.RcvrLock -> Detect. Recovery.RcvrLock
and Recovery.RcvrSpeed transit times are 24 ms and 48 ms respectively, so
the total time from L0 to Detect is ~96 ms. Increase the poll timeout to
120 ms to account for this.

While at it, add LTSSM state defines for Detect-related states and use them
in the poll condition. Use readl_poll_timeout() instead of
readl_poll_timeout_atomic() in tegra_pcie_dw_pme_turnoff() since that path
runs in non-atomic context.

Fixes: 56e15a238d92 ("PCI: tegra: Add Tegra194 PCIe support")
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://patch.msgid.link/20260324190755.1094879-3-mmaddireddy@nvidia.com